1. Technical Field
The present invention relates to a lens array substrate, in which the concave surfaces of the substrate are covered by a lens layer, an electro-optical device, an electronic apparatus, a micro-lens substrate manufacturing method, and an electro-optical device manufacturing method.
2. Related Art
In an electro-optical device (liquid crystal apparatus) which is used as the light valve or the like of a projection-type display apparatus, a liquid crystal layer is arranged between an element substrate, on which pixel electrodes and pixel switching elements are formed, and a counter substrate, on which common electrodes are formed. In the electro-optical device, a configuration is proposed in which a plurality of lenses that overlap the plurality of respective pixel electrodes in plan view are formed on one or both of the counter substrate and the element substrate in order to improve the quality of an image. In addition, in a case in which the lenses are formed, a technology is proposed in which lens surfaces, which include concave surfaces, are formed on a substrate, a lens layer is formed on the whole surfaces, and lenses are formed by flattening the surface of the lens layer (refer to JP-A-2004-258052). In the technology disclosed in JP-A-2004-258052, in a case in which the flattening is performed, the lens layer remains throughout all one surface of the substrate in addition to the insides of the concave surfaces. In the configuration, difference in the thickness of the lens layer is large in an in-plane direction of the substrate. Therefore, in a case in which high temperature is applied to the lens layer in a step that is performed after the lens layer is formed, stress is concentrated on the specific spots of the lens layer due to the difference in thickness. Since the stress causes cracks to be generated in the lens layer, the stress is not preferable. In contrast, in a case in which the lenses are formed, a technology is proposed in which lens surfaces, which include concave surfaces, are formed on one surface of a substrate, a lens layer is formed, and the lens layer is caused to selectively remain on the insides of the concave surfaces by polishing the lens layer (refer to JP-A-2003-185804).
In the technology disclosed in JP-A-2003-185804, in a case in which the lens layer is polished until the lens layer is completely broken between the lens surfaces, the surface of the substrate, which is positioned between adjacent lens surfaces, is also polished. Therefore, parts of the lens surfaces are polished, and thus a problem occurs in that the characteristics of the lenses are deteriorated.